Conventional image sensors are modules for converting an optical image into an electrical signal and are widely used in digital cameras, mobile phones with built-in cameras and similar devices.
A complementary metal-oxide semiconductor (CMOS) image sensor, which is a frequently used image sensor, converts an optical image into an electrical signal via a photodiode and CMOS transistors. The CMOS image sensor may be manufactured using semiconductor manufacturing technology.
Accordingly, research and development activities related to arrangement of components and wiring design are needed in order to improve not only the general characteristics, such as power consumption, range of use of signals, and noise, of CMOS image sensors, but also integration and quality of a semiconductor manufacturing process.